This invention relates to toothbrushes and in particular toothbrushes for use in oral hygiene systems suited for use by bedridden users.
Conventionally, water is applied to the bristled head of a toothbrush to assist the cleaning action of a dentifrice applied to its bristles, and following brushing, it is usual to rinse the mouth. To the able bodied or to those able to sit upright without undue difficulty, cleaning the teeth is not particularly troublesome.
However, when it is the case of a bedridden patient, not able to sit upright, or only able to sit upright with considerable difficulty and discomfort, cleaning the teeth is particularly troublesome, and especially rinsing the mouth, as neither the application of fluid to assist the action of the dentifrice nor subsequent rinsing of the mouth can be effected in conventional manner with the patient in the prone position.
It is known from such as U.S. Pat. No. 4,672,953 to provide a toothbrush with first and second passageway means through the handle for the supply of fluid to the bristles of the brush and its removal from the patient's mouth by suction, in an attempt to overcome the difficulties mentioned above in relation to patients who must, of necessity, remain in a prone position.
However, such a construction still leaves room for improvement in the sense that with prone patients it can frequently occur that the patient's mouth inadvertently closes on to the toothbrush during use causing an unrequired build-up of vacuum during removal of spent fluid. This problem is attended to in European Patent Number 0557337B where a toothbrush construction is provided that ensures that in the circumstance when a patient's mouth does inadvertently close on to the toothbrush there is the substantial guarantee that a vacuum build-up in the mouth is prevented.